Because nothing surprises us anymore, the reality of two brothers squaring off in the Super Bowl already has been trampled on by some as a tired narrative.
Cynics aside, Jim and John Harbaugh meeting on the NFL's biggest stage, if nothing else, remains a numerical rarity.
Kathy Ensor, a statistics professor and department chair at Rice University, placed the odds of this happening at 1 in 255.
"It's not very likely," she told the Houston Chronicle.
One in 255 doesn't sound that outrageous, but if you widen the pool to 150 coaches -- accounting for coordinators, ex-coaches and Bowl Championship Series coaches with the potential to reach the pro head-coaching level -- the odds jump to 1 in 11,175.
And when you factor in coaches from every level, Ensor described the chances as "astronomical."
We like football. We don't like math. We'll take her word for it.
Follow Marc Sessler on Twitter @MarcSesslerNFL.
